SEVERE WEATHER RISK: SLIGHT
TROPICAL STORM FORMATION: MEDIUM (50%)
ALL forecasts contained on this site, are based on my analysis and knowledge of various forecast tools, including information contained in NHC products, and are not copies from any other entity.
*NOTE: In the TROPICAL STORM FORMATION line above, probabilities are for during the next 5 day period. My personal probability will be listed as either NONE, MONITORING or PROBABLE. This does not necessarily mean something will develop, but that certain forecast conditions are likely to be present, favoring development. Once NHC products become available, then the appropriate probability and percentage will be used.
Please refer to the link for the Storm Prediction Center in the box at the top of the page, just below the Hurricane Hunter graphics.
Current Storm Total for 2015:
TOTAL STORMS: 1
INTENSE HURRICANES: 0
StormW Seasonal Forecast:
TOTAL STORMS: 8 – 10
HURRICANES: 3 – 5
INTENSE HURRICANES: 1 – 2
Good day everyone!
The area of disturbed weather over the Yucatan area that sparked my interest yesterday, has been designated INVEST 91L. AS of 18Z, the following information was available in the ATCF FTP product:
MOVEMENT: NW DRIFT
MIN. PRESSURE: 1009 MB / 29.80 IN
MAX SUSTAINED WIND: 35 MPH
The NHC has designated a MEDIUM (50%) probability of tropical cyclone formation over the next 5 days.
Clouds and convection have increased mainly to the north and east of the “center” over the past 24 hours, however the disturbance remains disorganized given the proximity to land, in addition to NWLY wind shear inhibiting development. It is noted however, in the upper level wind field overlay, that an outflow channel is present over the associated cloudiness.
I did notice, in satellite loop imagery, both RGB and the IR2 Shortwave channel in the floater imagery, it appears a competing low is present and noted near 20.0N;89.3W over the Yucatan Peninsula. It is not uncommon in weak systems to have multiple vorticies swirling about, competing for energy from the main center. I was just informed by a colleague, that the 21Z position of the low IS IN FACT over the Yucatan Peninsula. This could most likely mean a shift in the track guidance in the 00Z run.
You must click on the satellite images in order to view the loops.
Based on my analysis of current wind shear forecast maps, development of this system once it enters the GOMEX should be somewhat slow to occur. The forecast currently shows upper level winds to remain mostly unfavorable during the next 30 – 40 hours, however are forecast to become marginally favorable for development, with a very small area of zero zonal wind shear centered over the system. Based on this, and if it holds true to form, I have to agree with the current run of the Intensity Forecast Models solution of a strong tropical depression. However, I will not rule out a minimal Tropical Storm force system should upper level winds become more favorable. One other thing to keep in the back of your mind, especially with systems that develop closer to the coast of Mexico, or southern BOC…given the shape of the coastline, this has a tendency to create what we term as forced convergence, as the coastline has a tendency to direct surface wind flow into the storm. This is how some storms are able to recover after weakening over the Yucatan, or how some storms ramp up so quickly.
Based on current and forecast steering maps, I agree at the moment with the 18Z ATCF Dynamic Model Guidance for 91L, preferring the current TVCN / TVCC forecast track, however with a center relocation, this will most likely change. These tracks should be considered preliminary, until we see this begin developing over the water, and models have more time to perform subsequent runs.
Right now, it appears as if the heaviest of weather may remain on the east side of the system, and away from the center, unless it becomes much better organized.
Residents from Corpus Christie to Port Arthur should monitor the progress of this system over the next 48 – 60 hours for any significant changes if they occur.
I will continue to monitor this system closely, and will have another update tomorrow, hopefully before noon.
Have a blessed day!
T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST / SEVERE WEATHER SPECIALIST MEMBER WEST CENTRAL FLORIDA AMS